Prof. Sigurd Skogestad, NTNU
PID is the future of advanced control
This talk explains why “advanced regulatory control” (ARC), where the PID controller is a central component, should be the preferred solution for future advanced control.
The main competitor to ARC is MPV (model predictive control), but the costs of implementing and maintaining MPC solutions are high. Moreover, in most cases ARC solutions (including cascade, ratio, split range and selector control) are more flexible and easier to tune. The main problem right now is that the knowledge and competence about ARC strategies is very low, especially in academia, but also in industry the knowledge is dying out. The result is that people turn off good ARC applications, simply because they don’t understand what they are doing.
The reason for the lack of training and knowledge is that there has a been belief in academia since the 1980s, that ARC solutions (and PID control) are old-fashioned and will soon be replaced by MPC. However, MPC has now been around for 50 years, and yet the use of MPC is far from increasing as expected. The latest belief is that, if MPC is too complex, then machine learning is the solution. No, it is not, because or the lack of rich data (with sufficiently large input excitations) in most control applications, in particular in process control.
In summary, there is a need to change the mindset of people, both in academia and industry, People need to realize that ARC solutions should be a central part of the future. MPC of course has its place, but mainly as an improvement for large-scale applications that can afford the effort.
The talk will emphasize the above points and in addition present a systematic approach to ARC methods based on my recent paper (which is open access).
Reference:
Sigurd Skogestad, Advanced control using decomposition and simple elements, Annual Reviews in Control, volume 56 (2023), 100903